Messages in this thread Patch in this message |  | | | From | Darren Hart <> | | Subject | [PATCH 1/4] rtmutex: avoid null derefence in WARN_ON | | Date | Fri, 9 Jul 2010 15:32:57 -0700 |
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If the pi_blocked_on variable is NULL, the subsequent WARN_ON's will cause an OOPS. Only perform the susequent checks if pi_blocked_on is valid.
Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: John Kacur <jkacur@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mike Galbraith <efault@gmx.de> --- kernel/rtmutex.c | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c index 23dd443..baac7d9 100644 --- a/kernel/rtmutex.c +++ b/kernel/rtmutex.c @@ -579,9 +579,10 @@ static void wakeup_next_waiter(struct rt_mutex *lock, int savestate) raw_spin_lock(&pendowner->pi_lock); - WARN_ON(!pendowner->pi_blocked_on); - WARN_ON(pendowner->pi_blocked_on != waiter); - WARN_ON(pendowner->pi_blocked_on->lock != lock); + if (!WARN_ON(!pendowner->pi_blocked_on)) { + WARN_ON(pendowner->pi_blocked_on != waiter); + WARN_ON(pendowner->pi_blocked_on->lock != lock); + } pendowner->pi_blocked_on = NULL; -- 1.7.0.4
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